1. Field of the Invention
The present invention generally relates to a display apparatus for controlling a position of a coloring charged particle and displaying an image.
2. Related Background Art
In recent years, a liquid crystal panel has broadly been utilized as a display apparatus for displaying an image.
The liquid crystal panel has little power consumption and is superior in mobile property. Moreover, the panel does not easily tire eyes as compared with a cathode ray tube (CRT), light emitting diode (LED), and the like. On the other hand, a type of the liquid crystal panel which does not use a back light has a problem of bad contrast, and a type which uses the back light easily tires the eyes (as compared with the type which does not use the back light).
Then, as a display apparatus for solving these problems, an electrophoresis display apparatus has been proposed in Japanese Patent Application Laid-Open No. 1-222292.
As shown in FIG. 31, the display apparatus comprises a pair of substrates 4a, 4b which are disposed at a predetermined gap, the gap is filled with an insulating liquid 1 formed of xylene, dye, and surface-active agent, and coloring charged particles 2 such as TiO2 particles are further dispersed in the gap. Moreover, a voltage applied to the coloring charged particles 2 is controlled by a unit of pixel so that positions of the particles are controlled, and the image is entirely displayed in this constitution.
Additionally, reference numerals 400a, 400b denote transparent electrodes which are disposed so as to hold the coloring charged particles 2 and insulating liquid 1 therebetween and to which a constant voltage is applied, 10 denotes a photoconductive layer (a-SiC layer), and 12 denotes a light emitting diode array for irradiating the photoconductive layer 10 with light. In this apparatus, while the constant voltage is applied to the pair of transparent electrodes 400a, 400b, and the photoconductive layer 10 is irradiated with the light from the light emitting diode array 12, a carrier is generated in the photoconductive layer 10, and an electric field strength between the photoconductive layer 10 and the transparent electrode 400b increases. However, while the light emitting diode array 12 is moved along the substrate 4b in a direction of an arrow 401, irradiation/non-irradiation is controlled by the unit of pixel. Thereby, the positions of the coloring charged particles 2 can be controlled by the unit of pixel.
Additionally, in the aforementioned electrophoresis display apparatus, a space between the pixels is partitioned by a spacer 402, so that the coloring charged particles 2 are prevented from moving to other pixels, the number of coloring charged particles 2 in each pixel is prevented from changing, and display quality just after manufactured is maintained.
However, it is very difficult to dispose an equal amount of coloring charged particles 2 in the respective pixels partitioned by the spacer 402. Therefore, when the number of coloring charged particles 2 is not uniform, the display quality is disadvantageously deteriorated.
Moreover, when the space between the pixels is partitioned by the spacer 402, the insulating liquid 1 is not agitated. Therefore, micro particles adhere to one another, display unevenness easily occurs by sedimentation, and it is difficult to secure stability with an elapse of time. Furthermore, since the spacer 402 is disposed, an aperture ratio is deteriorated, flexibility of the display apparatus is deteriorated, and the display apparatus is thickened.